21002

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 49.at n=27A020388
• Number of compositions (ordered partitions) of n into distinct odd parts.at n=54A032021
• Lexicographically earliest strictly increasing base 3 autovarious sequence: a(n) = number of distinct a(k) mod 3^n (written in base 3).at n=26A037091
• In the list of divisors of n (in base 3), each digit 0-2 appears equally often.at n=12A045811
• Primes of form 4k+3 written in base 3.at n=22A072805
• Binary numbers with 2 replacing 1 in odd positions.at n=25A095914
• Ceiling(n*exp(sec n)).at n=13A134898
• Numbers 3*n + 2 written in base 3.at n=63A190642
• Number of n element 1..n arrays with each element the minimum of 4 adjacent elements of a permutation of 1..n+3 of n+3 elements.at n=7A217887
• T(n,k) is the number of n element 1..n arrays with each element the minimum of k adjacent elements of a permutation of 1..n+k-1 of n+k-1 elements.at n=62A217891
• Not necessarily palindromic primes of which initial and terminal digits are identical, as written in base 3.at n=18A231278
• Coefficients in expansion of (q*j(q))^(-1/6) where j(q) is the elliptic modular invariant (A000521).at n=2A299828